Another lens to consider for wide angle shooting is the Sigma 10-20mm lens which is available in a fourthirds mount. It sells for around 480 USD. I don't know how that translates to Canadian currency.

I own the 12-60mm SWD lens and find it to be about as good a lens as I've ever used. Even though I would like to add a 9-18mm, The add'l angle of view of the 9-18mm is just not that compelling enough to me, at this point, to buy it.

There are a number of forum members who have the 9-18 as well as the 11-22mm. I''m sure they will provide you with their insights and samples.
Zig

The 11-22 Zuiko is probably the best compromise. Not as wide as the 7-14, but much easier to use and spectacular image quality. For the optics and speed, I'd easily pay the difference for it over the 10-20 Sigma.

The 9-18 Zuiko is very nice and so lightweight, so it's easy to carry. That's why I have it, and that's the biggest plus compared to the 11-22, which is on a much higher level of build-quality and so weighs more. If I were to have to replace my 12-60, I'd do it with the 11-22. I pretty much treat the 9-18 as a 9mm prime since the 12-60 has much of the rest of the range covered.

folob, I have the 9-18mm. although I just had to send it in for repair it is light & easy to carry & has fairly decent image quality but no where near the quality of glass the 12-60mm is. for my use the 9-18mm is good & you can get great results with it. takes a little extra post processing to get the sharpness & contrast right (Also distortion if that bothers you). I have said previously I would have gone with the 11-22mm if I had to do it over again. but the 9-18mm's weight makes it hard to give it up for what I use it for(hiking/landscapes/waterfalls).

As far as faster aperture of the 11-22mm at this wide I personally think that is a mute point, the 11-22mm gives you superior optics & distortion correction & is weatherproofed that is its real advantages.